GRP fibreglass roofing across County Tyrone

Price per m²

£66–£123

Typical life

20–40 years

Manufacturer guarantees

20–25 year material warranties on specified systems

Typical garage roof

£1,550–£2,850

How much does a GRP fibreglass roof cost in County Tyrone?

Guide prices including VAT at Northern Ireland rates. The fixed price comes after a free survey for new and replacement roofs.

Which flat roofs are common in County Tyrone?

Flat roofs in County Tyrone sit on lock-up garage blocks on estates, shops with flat-roofed rear stores below flats and 1960s and 1970s link-detached houses with flat-roofed garages and porches. Northern Ireland averages roughly 1,150 mm of rain a year, spread over many wet days, so a roof that sheds water quickly to clear outlets lasts far longer than one that holds puddles. Approximate 1991–2020 regional averages based on Met Office data.

Building control in Northern Ireland

In Northern Ireland, renovating or replacing a roof over a heated room usually means meeting Technical Booklet F1, and building control should be contacted before work starts. Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where feasible. In County Tyrone the application goes to Fermanagh and Omagh District Council, Derry City and Strabane District Council and Mid Ulster District Council. More on the rules.

Why do GRP roofs crack, and can weather affect the installation?

GRP usually cracks where the structure moves and the laminate cannot, typically along board joints, at the junction with trims, or where a roof meets a wall. Weather during laying is the other big factor, because resin cures by chemical reaction and that reaction is sensitive to temperature and moisture.

How we reduce the risk of cracking:

• boards fixed at close centres so the deck does not flex;
• joints taped and reinforced with an extra strip of mat;
• wall junctions finished with a separate trim or flashing, not laminated hard into the masonry;
• roofs over a certain size divided with movement details where the system calls for them.

And how weather is managed:

• no laminating in rain, on a damp deck, or when dew or frost is likely before the resin sets;
• catalyst levels adjusted for the temperature, so resin neither stays tacky on a cold day nor kicks too fast in summer heat;
• the roof sheeted over if a shower threatens a fresh laminate.

That is why a GRP date can move at short notice. A day's delay costs far less than a laminate that never cures properly.

Will a new GRP roof need extra insulation to meet building regulations?

If the roof is over a heated room and you are replacing more than half of it, usually yes. In England, Wales and Northern Ireland that counts as renovating a thermal element, and in Scotland the council's building standards service will say whether a building warrant applies.

GRP pairs well with a warm roof because the new deck boards it needs can sit on top of the insulation. The result is thicker, so we check at survey that there is room under door cills and wall flashings, and that the upstands can finish around 150 mm above the new surface. Where approval is needed we arrange it with building control or building standards.

Unheated, detached garages normally sit outside the thermal rules. See the building regulations page for each nation, or the warm vs cold roof guide for why we avoid cold roofs where we can.

Which towns in County Tyrone do we cover?

• Omagh
• Strabane
• Dungannon
• Cookstown

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